U.S. patent application number 15/734021 was filed with the patent office on 2021-07-22 for stretchable wiring member.
This patent application is currently assigned to SEKISUI POLYMATECH CO., LTD.. The applicant listed for this patent is SEKISUI POLYMATECH CO., LTD.. Invention is credited to Takaya Kimoto.
Application Number | 20210227689 15/734021 |
Document ID | / |
Family ID | 1000005552701 |
Filed Date | 2021-07-22 |
United States Patent
Application |
20210227689 |
Kind Code |
A1 |
Kimoto; Takaya |
July 22, 2021 |
Stretchable Wiring Member
Abstract
In a stretchable wiring member having a relatively hard portion,
such as a contact point, there is provided a solution to
malfunction of the stretchable wiring member caused by stress
generated at a boundary between the hard portion and a flexible
portion. A stretchable wiring member includes a flexible substrate
having stretchability, a stretchable wiring line disposed along the
flexible substrate and configured to be stretched in association
with stretching deformation of the flexible substrate, and a hard
member that is harder than the flexible substrate. The flexible
substrate has an extension layer portion interposed between the
hard member and the stretchable wiring line.
Inventors: |
Kimoto; Takaya; (Saitama,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SEKISUI POLYMATECH CO., LTD. |
Saitama |
|
JP |
|
|
Assignee: |
SEKISUI POLYMATECH CO.,
LTD.
Saitama
JP
|
Family ID: |
1000005552701 |
Appl. No.: |
15/734021 |
Filed: |
June 28, 2019 |
PCT Filed: |
June 28, 2019 |
PCT NO: |
PCT/JP2019/025973 |
371 Date: |
December 1, 2020 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H05K 1/0283 20130101;
H05K 1/09 20130101; A61B 5/268 20210101; H05K 1/11 20130101; H05K
2201/10151 20130101 |
International
Class: |
H05K 1/02 20060101
H05K001/02; H05K 1/11 20060101 H05K001/11; H05K 1/09 20060101
H05K001/09; A61B 5/268 20060101 A61B005/268 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 28, 2018 |
JP |
2018-122745 |
Claims
1. A stretchable wiring member comprising: a flexible substrate
having stretchability; a stretchable wiring line disposed along the
flexible substrate and configured to be stretched in association
with stretching deformation of the flexible substrate; and a hard
member that is harder than the flexible substrate, wherein the
flexible substrate has an extension layer portion interposed
between the hard member and the stretchable wiring line.
2. The stretchable wiring member according to claim 1, wherein the
hard member has a recess formed at a position between the hard
member and the stretchable wiring line, and the extension layer
portion is disposed in the recess.
3. The stretchable wiring member according to claim 1, wherein the
hard member is an electroconductive member.
4. The stretchable wiring member according to claim 1, wherein the
hard member is an electrode.
5. The stretchable wiring member according to claim 1, wherein the
hard member is electrically connected to the stretchable wiring
line.
6. The stretchable wiring member according to claim 1, wherein the
hard member is an electroconductive rubber that is made of at least
one of a thermosetting rubber and a thermoplastic elastomer and in
which an electroconductive filler is dispersed.
7. The stretchable wiring member according to claim 1, wherein the
stretchable wiring line extends from an outer periphery of the hard
member in two opposite directions.
8. The stretchable wiring member according to claim 1, wherein the
stretchable wiring line is spaced from the hard member in a
thickness direction of the flexible substrate, and the stretchable
wiring member further comprises an isolation portion that isolates
the stretchable wiring line from the hard member.
9. The stretchable wiring member according to claim 1, wherein the
hard member is an insulating member.
10. The stretchable wiring member according to claim 1, wherein the
extension layer portion has a portion near the center of the hard
member and an outer portion as viewed in plan, and the outer
portion is formed to be thicker than the portion near the center of
the hard member.
11. The stretchable wiring member according to claim 1, wherein the
flexible substrate and the stretchable wiring line contain a
silicone rubber component.
Description
TECHNICAL FIELD
[0001] The present invention relates to a stretchable wiring member
having a flexible substrate and stretchable wiring lines disposed
at the flexible substrate.
BACKGROUND ART
[0002] Wearable devices, such as smart watches, activity meters, or
pulsimeters, have been developed widely in recent years. Such
wearable devices are equipped with sensors for measuring body
conditions and activities, for example, by taking the pulse or by
counting the number of walking steps. A typical wearable device
includes a unit in which semiconductor devices are arranged in a
flexible substrate or a rigid substrate. Such a wearable device
does not follow body movement and may give an uncomfortable wearing
feeling. On the other hand, a technique for obtaining a flexible
wearable device has been developed. Such a flexible wearable device
uses a stretchable wiring member in which stretchable
electroconductive wires are formed on an elastic member or clothes
having stretchability.
[0003] The stretchable wiring member used for the wearable device
still has hard electrodes that serve as contact points. In this
case, when the stretchable wiring member is stretched, stress is
concentrated at the boundary between a contact point and the
flexible substrate, which may cause the contact point to detach
from the flexible substrate. If a stretchable electroconductive
wire is laminated on a detached portion, the wire may break
simultaneously with detachment. To solve this problem, disposing a
reinforcement member is proposed by Japanese Unexamined Patent
Application Publication No. 2012-033597 (PTL 1) and also by
Japanese Unexamined Patent Application Publication No. 2016-145725
(PTL 2).
CITATION LIST
Patent Literature
[0004] PTL 1: Japanese Unexamined Patent Application Publication
No. 2012-033597 [0005] PTL 2: Japanese Unexamined Patent
Application Publication No. 2016-145725
SUMMARY OF INVENTION
Technical Problem
[0006] However, disposing the reinforcement member proposed by
Japanese Unexamined Patent Application Publication No. 2012-033597
(PTL 1) or by Japanese Unexamined Patent Application Publication
No. 2016-145725 (PTL 2) requires an area for fixation, which is not
advantageous from the view point of size reduction. Accordingly, an
object of the present invention is to provide another solution to
the problem caused by stress generated at the boundary between a
hard portion such as a contact point and a stretchable flexible
portion that are included in a stretchable wiring member.
Solution to Problem
[0007] To solve the above problem, a stretchable wiring member
according to an aspect of the present invention is configured as
follows. The stretchable wiring member includes a flexible
substrate having stretchability, a stretchable wiring line disposed
along the flexible substrate and configured to be stretched in
association with stretching deformation of the flexible substrate,
and a hard member that is harder than the flexible substrate. In
the stretchable wiring member, the flexible substrate has an
extension layer portion interposed between the hard member and the
stretchable wiring line.
[0008] The stretchable wiring member has the extension layer
portion interposed between the hard member and the stretchable
wiring line, which can prevent the stretchable wiring line from
breaking easily.
[0009] In the case in which the flexible substrate has the hard
member such as an electrode and the stretchable wiring line is
connected to the electrode, there arises a problem that the
stretchable wiring line breaks easily at the boundary with the
electrode. However, providing the extension layer portion between
the hard member and the stretchable wiring line causes the flexible
substrate to start to stretch from the extension layer portion
laminated on the hard member. As a result, the stretch of the
flexible substrate does not start abruptly at the peripheral edge
of the hard member but starts from a portion laminated on the hard
member, which can reduce the stress concentrated on the stretchable
wiring line at the boundary. Thus, the stretchable wiring member
can prevent the stretchable wiring line from breaking easily.
Accordingly, the stretchable wiring member, which does not use the
reinforcement member of the known technique, can solve the problems
of thickness and area increase and deterioration of the external
appearance in association with provision of the reinforcement
member.
[0010] The hard member may have a recess formed at a position
between the hard member and the stretchable wiring line, and the
extension layer portion may be disposed in the recess. Since the
hard member has the recess, the extension layer portion can be
formed as a lump that fills recess. The extension layer portion
formed as the lump can be stretched more flexibly compared with an
extension layer portion being simply formed as a thin layer between
the hard member and the stretchable wiring line. When the hard
member is about to be detached from the flexible substrate at the
boundary therebetween in the stretchable wiring member, the
extension layer portion serves as a buffer layer and can prevent
the stretchable wiring line from breaking easily.
[0011] The hard member may be an electroconductive member. Since
the hard member is the electroconductive member, the stretchable
wiring member can be configured such that the stretchable wiring
line is electrically connected to the hard member.
[0012] The hard member may be an electrode. Since the hard member
is the electrode, the extension layer portion can be formed at the
electrode of the stretchable wiring member. By disposing the
extension layer portion between the flexible substrate and the
electrode, the stretchable wiring member can reduce the stress
generated at the boundary between the flexible substrate and the
electrode and can prevent the stretchable wiring line from breaking
easily even if the stretchable wiring member does not have the
reinforcement member.
[0013] The hard member may be electrically connected to the
stretchable wiring line. Since the hard member is electrically
connected to the stretchable wiring line, the stretchable wiring
member can be configured to have the extension layer portion at the
boundary between the stretchable wiring line and the hard member.
Accordingly, the stretchable wiring member can prevent the
stretchable wiring line from breaking easily in the vicinity of the
boundary at which the stretchable wiring line is connected to the
hard member.
[0014] The hard member may be an electroconductive rubber that is
made of at least one of a thermosetting rubber and a thermoplastic
elastomer and in which an electroconductive filler is dispersed. In
the stretchable wiring member, deformation of the electroconductive
rubber can reduce part of the stress generated at the boundary
between the hard member and the flexible substrate compared with a
case in which the hard member is made, for example, of a hard resin
or a metal. Accordingly, the stretchable wiring member can further
prevent the stretchable wiring line from breaking easily in the
vicinity of the boundary at which the stretchable wiring line is
connected to the hard member.
[0015] The stretchable wiring line may extend from an outer
periphery of the hard member in two opposite directions. With this
configuration, the hard member can be disposed at an intermediate
portion of the stretchable wiring line in the stretchable wiring
member.
[0016] The stretchable wiring line may be spaced from the hard
member in a thickness direction of the flexible substrate, and the
stretchable wiring member may further include an isolation portion
that isolates the stretchable wiring line from the hard member. The
stretchable wiring line is spaced from the hard member, and the
isolation portion that has no contact portion between the
stretchable wiring line and the hard member is provided.
Accordingly, even if the hard member is an electroconductive
member, the stretchable wiring line can be laminated on the hard
member while preventing an electrical connection between the
stretchable wiring line and the hard member. Accordingly, multiple
stretchable wiring lines can be disposed densely in a narrow area
in the stretchable wiring member.
[0017] When stretchable wiring lines are patterned, using screen
printing or the like, on a flexible substrate on which multiple
contact point members are disposed, it is usually necessary to
dispose a stretchable wiring line connected to a contact point
member in such a manner that the stretchable wiring line detours
around other contact point members. In this case, if a flexible
substrate is, for example, shaped like a strip, it is necessary to
dispose stretchable wiring lines near a side edge of the strip,
which makes it difficult to dispose electrodes across the full
width of the strip. In other words, disposing the stretchable
wiring lines that detour around the electrodes requires an
additional area, which inevitably increases the width of the strip.
The stretchable wiring member, however, has the extension layer
portions, and the extension layer portions enable stretchable
wiring lines to be laminated on the electrodes without electrical
connection therebetween.
[0018] The hard member may be an insulating member. Also in the
case of the hard member serving as the insulating member, provision
of the extension layer portion can prevent the stretchable wiring
line from breaking easily. In other words, even in the case in
which the stretchable wiring line is connected to the insulating
member instead of the electroconductive member such as an
electrode, the stretchable wiring line can be prevented from
breaking easily. It may be necessary to connect the stretchable
wiring line not only to the electroconductive member such as an
electrode but also to an insulating member formed as, for example,
a button having no electroconductivity. Even in this case, the
stretchable wiring line can be prevented from breaking easily near
the boundary between the insulating member and the stretchable
wiring line.
[0019] The extension layer portion has an inner portion and an
outer portion, in which the inner portion and the outer portion are
defined with respect to the position in a projected area onto which
the hard member is projected, and the outer portion may be formed
to be thicker than the inner portion. In other words, the extension
layer portion has a portion positioned near the center of the hard
member and an outer portion when the hard member is viewed in plan,
and the outer portion may be formed to be thicker than the portion
near the center. With respect to the position in the projected
area, the outer portion of the extension layer portion is formed to
be thicker than the inner portion thereof. In other words, as
viewed in plan, the extension layer portion has the portion
positioned near the center of the hard member and the outer
portion, and the outer portion is formed to be thicker than the
portion near the center. With this configuration, the volume of the
extension layer portion can be reduced compared with a case of an
extension layer portion being formed so as to have a constant
thickness. Also in this case, the stretchable wiring line can be
effectively prevented from breaking easily. By changing the shape
of the hard member, the outer portion of the extension layer
portion can be made thicker easily than the inner portion with
respect to the position in the projected area, in other words,
thicker than the portion near the center of the hard member as
viewed in plan, which leads to easy manufacturing.
[0020] The flexible substrate and the stretchable wiring line may
contain a silicone rubber component. The flexible substrate and the
stretchable wiring line contain the silicone rubber component,
which improves adhesion between the flexible substrate and the
stretchable wiring line and accordingly can prevent easy breakage
of the stretchable wiring line.
Advantageous Effects of Invention
[0021] According to the present invention, the stretchable wiring
line can be prevented from breaking easily.
BRIEF DESCRIPTION OF DRAWINGS
[0022] FIG. 1 is a schematic plan view illustrating a stretchable
wiring member according to a first embodiment, in which a flexible
substrate is assumed to be transparent.
[0023] FIG. 2 is a cross-section of the stretchable wiring member
taken along line II-II in FIG. 1.
[0024] FIG. 3 is a diagram for explanation of a manufacturing
method of the stretchable wiring member of FIG. 1.
[0025] FIG. 4 are views illustrating portions of a stretchable
wiring member according to a modification example 1-1, in which
FIG. 4A is a partially enlarged plan view corresponding to a
partially enlarged region R2 of FIG. 1 and FIG. 4B is a partially
enlarged cross-sectional view corresponding to a partially enlarged
region R5 of FIG. 2.
[0026] FIG. 5 is a schematic plan view illustrating a stretchable
wiring member according to a second embodiment, in which a flexible
substrate is assumed to be transparent.
[0027] FIG. 6 are cross-sectional views illustrating the
stretchable wiring member of FIG. 5, in which FIG. 6A is a cross
section taken along line VIA-VIA in FIG. 5 and FIG. 6B is a
cross-sectional view taken along line VIB-VIB in FIG. 5.
[0028] FIG. 7 is a schematic plan view illustrating a stretchable
wiring member according to a third embodiment, in which a flexible
substrate is assumed to be transparent.
[0029] FIG. 8 are cross-sectional views illustrating the
stretchable wiring member of FIG. 7, in which FIG. 8A is a cross
section taken along line VIIIA-VIIIA in FIG. 7 and FIG. 8B is a
cross section taken along line VIIIB-VIIIB in FIG. 7.
[0030] FIG. 9 are cross-sectional views illustrating the
stretchable wiring member of FIG. 7, in which FIG. 9A is a cross
section taken along line IXA-IXA in FIG. 7 and FIG. 9B is a cross
section taken along line IXB-IXB in FIG. 7.
[0031] FIG. 10 is a cross-sectional view illustrating a stretchable
wiring member according to a fourth embodiment, which corresponds
to the cross-sectional view of FIG. 2.
[0032] FIG. 11 is a partially enlarged cross-sectional view
illustrating a stretchable wiring member according to a
modification example 4-1, which corresponds to a partially enlarged
region R14 of FIG. 10.
[0033] FIG. 12 are views illustrating portions of a stretchable
wiring member according to a fifth embodiment, in which FIG. 12A is
a bottom view of an essential part of the stretchable wiring member
and FIG. 12B is a cross section taken along line XIIB-XIIB in FIG.
12A.
[0034] FIG. 13 are cross-sectional views for explanation of
modification examples of an extension layer portion, in which any
of FIGS. 13A to 13C corresponds to the partially enlarged region R5
of FIG. 2.
DESCRIPTION OF EMBODIMENTS
[0035] Example embodiments according to the present invention will
be described with reference to the drawings. Note that the
descriptions of the same material, composition, production method,
advantageous effects, or the like will not be repeated for each
embodiment described below. In addition, terms such as "first",
"second", "third", or the like, will be used in the specification
or in the appended claims with an intension to differentiate
elements of the invention from each other and not with an intension
to indicate a specific order nor to indicate that one is superior
or inferior to another.
First Embodiment [FIGS. 1 to 3]
[0036] A stretchable wiring member 11 according to the present
embodiment will be described. FIG. 1 is a plan view of the
stretchable wiring member 11 in which a flexible substrate 20 (to
be described later) is assumed to be transparent. FIG. 2 is a
cross-sectional view of the stretchable wiring member 11. The
stretchable wiring member 11 includes a flexible substrate 20 that
is stretchable and stretchable wiring lines 30 that are laminated
on the flexible substrate 20. The stretchable wiring member 11
further includes contact point members 40 that include an
electroconductive rubber connector 50, a body sensor 60, and a
second connector 70. The electroconductive rubber connector 50 is
electrically connected to the stretchable wiring lines 30. The
contact point members 40 of the present embodiment are formed as
hard members that are harder than the flexible substrate 20. Next,
portions constituting the stretchable wiring member 11 will be
described below.
[0037] Flexible Substrate 20: The flexible substrate 20 is a
stretchable base member (stretchable substrate) that supports the
stretchable wiring lines 30. The flexible substrate 20 is made of a
flexible material, such as a thermosetting rubber or a
thermoplastic elastomer, having insulating properties. The flexible
substrate 20 is made of a stretchable material having such a
stretchability that the flexible substrate 20 can return to its
initial length after stretched at least to 120% or more, more
preferably to 150% or more, of the initial length.
[0038] It is preferable that the hardness of the thermosetting
rubber and thermoplastic elastomer be 90 or less in terms of
A-hardness defined in JIS K6253 ("90" in this meaning is
hereinafter termed as "A90"). If the rubber hardness exceeds A90,
it may become difficult to achieve high stretchability because the
stress generated by stretching becomes greater than necessary. The
rubber hardness is preferably in the range of A0 to A70 from a view
point of better stretchability, and more preferably in the range of
A20 to A50 from a view point of better combination of
stretchability and handling easiness.
[0039] The flexible substrate 20 may be shaped like a strip or a
stick. The flexible substrate 20 may be made wide at a portion, and
its vicinity, to which each contact point member 40 is fixed. The
wide portion formed near each contact point member 40 can reduce
the rate of extension of the flexible substrate 20 near the
boundaries between the stretchable wiring lines 30 and each contact
point member 40.
[0040] Stretchable Wiring Line 30: The stretchable wiring lines 30
are disposed in the flexible substrate 20 and can be stretched
together with the flexible substrate 20. In the stretchable wiring
member 11, the electroconductive rubber connector 50 and the second
connector 70 are disposed at respective end portions of the
flexible substrate 20 and electrically connected by the stretchable
wiring lines 30 to the body sensors 60 disposed at the center of
the flexible substrate 20. Accordingly, the electrical connection
between the body sensors 60 and the electroconductive rubber
connector 50 or the second connector 70 can be maintained in spite
of changing the distance (length) between the body sensors 60 and
the electroconductive rubber connector 50 or between the body
sensors 60 and the second connector 70. Although the stretchable
wiring lines 30 may be formed on the surface of the flexible
substrate 20, the stretchable wiring lines 30 are preferably buried
in the flexible substrate 20. The stretchable wiring lines 30 are
thereby protected.
[0041] Each stretchable wiring line 30 is made of an
electroconductive material having stretchability. More
specifically, the stretchable wiring line 30 may be made of a
flexible electroconductive resin in which an electroconductive
filler, such as a silver filler, is dispersed in a thermosetting
rubber or a thermoplastic elastomer. In the case of the flexible
substrate 20 being made of a thermosetting rubber or a
thermoplastic elastomer, the stretchable wiring line 30 is
preferably made of a flexible electroconductive resin in which
silver powder or carbon powder is dispersed in the same type of
resin. This improves adherence between the flexible substrate 20
and the stretchable wiring line 30.
[0042] Both of the stretchable wiring line 30 and the flexible
substrate 20 are made of flexible materials. The hardnesses of both
materials can be set to be the same. The hardness of the
stretchable wiring line 30, however, may be set higher than the
hardness of the flexible substrate 20. In the stretchable wiring
member 11 with this hardness configuration, when the stretchable
wiring member 11 is compressed, the flexible substrate 20 is more
vulnerable to compressive deformation than the stretchable wiring
line 30. The stretchable wiring line 30 thereby do not change in
volume easily. Accordingly, in an application in which the
stretchable wiring member 11 is subjected to pressure in a
direction different from the stretching direction, the stretchable
wiring line 30 can exhibit stable electric resistance.
[0043] It is preferable that the adhesive strength between the
stretchable wiring line 30 and the flexible substrate 20 be set to
be greater than the tensile strength at break of the stretchable
wiring line 30. If the tensile strength at break of the stretchable
wiring line 30 is greater than the adhesive strength between the
stretchable wiring line 30 and the flexible substrate 20, the
stretchable wiring line 30 may be detached from the flexible
substrate 20 when the stretchable wiring member 11 is elongated
largely, for example, to a level exceeding 200%. In this case, the
stretchable wiring line 30 deforms largely in the lateral direction
thereof. Stresses are thereby generated between the stretchable
wiring line 30 and the flexible substrate 20, which possibly causes
the stretchable wiring line 30 to detach more readily.
[0044] To address this problem, the tensile strength at break of
the stretchable wiring line 30 is set to be smaller than the
adhesive strength between the stretchable wiring line 30 and the
flexible substrate 20. As a result, cracks can occur in part of the
stretchable wiring line 30 before the stretchable wiring line 30 is
detached from the flexible substrate 20. These cracks, which are
normally small, may cause the electric resistance to increase but
do not easily lead to large cracks that break the stretchable
wiring line 30. The breaking of the stretchable wiring line 30 can
be thereby suppressed while suppressing the detachment of the
stretchable wiring line 30. Moreover, the elongation limit of the
stretchable wiring line 30 is detectable by monitoring the increase
of electric resistance of the stretchable wiring line 30.
[0045] The above relationship between the adhesive strength and the
tensile strength at break can be determined by performing tension
tests on the stretchable wiring member 11 and observing crack
generation in the stretchable wiring line 30 before the stretchable
wiring line 30 is detached. In other words, if the stretchable
wiring line 30 is detached before cracks are generated in the
stretchable wiring line 30, the tensile strength at break of the
stretchable wiring line 30 can be regarded as being greater than
the adhesive strength between the stretchable wiring line 30 and
the flexible substrate 20. On the other hand, if cracks are
generated in part of the stretchable wiring line 30 before the
stretchable wiring line 30 is detached, the adhesive strength
between the stretchable wiring line 30 and the flexible substrate
20 can be regarded as being greater than the tensile strength at
break of the stretchable wiring line 30.
[0046] Contact Point Member 40: The contact point members 40 are
connector portions of the stretchable wiring member that
electrically connect the stretchable wiring lines 30 to connection
objects P, such as a human body or an electronic device or
component like a circuit board. The material used for the
electroconductive portion of each contact point member 40 may be,
for example, a metal, a carbon material, an electroconductive
resin, an electroconductive rubber, or other electroconductive
materials. Among these, the electroconductive resin is a resin in
which an electroconductive filler is dispersed. The
electroconductive rubber is a thermosetting rubber or a
thermoplastic elastomer in which an electroconductive filler is
dispersed. The electroconductive material is insulating resin
particles or the like coated with a metal. It is preferable that
the metal and the electroconductive filler described above be
stable materials having such a high corrosion resistance that the
metal and the electroconductive filler exhibit sufficient
weatherability and durability even when the contact point member 40
is exposed out of the stretchable wiring member 11. For example, a
noble metal such as gold or an alloy such as stainless steel, or
carbon powder can be used for this purpose.
[0047] The stretchable wiring member 11 of the present embodiment
uses three types of the contact point members 40, in other words,
the electroconductive rubber connector 50, the body sensors 60, and
the second connector 70. Each contact point member 40 has a hard
portion that is harder than the flexible substrate 20.
[0048] Electroconductive Rubber Connector 50: Among the connector
portions of the stretchable wiring member 11 for electrical
connection with the connection objects P, such as a circuit board,
the electroconductive rubber connector 50 is a portion that
includes an electrode 51 formed of an electroconductive rubber
composite in which an electroconductive filler is dispersed in a
rubber-like polymer.
[0049] The electroconductive rubber connector 50 has a first
contact end 51a to be electrically connected to a connection object
P and a second contact end 51b to be electrically connected to the
stretchable wiring line 30. The electroconductive rubber connector
50 has the electrode 51 formed between the first contact end 51a
and the second contact end 51b, and the electrode 51 electrically
connects the connection object P to the stretchable wiring line 30.
The electroconductive rubber connector 50 is deformable in the
direction of the electrode 51 extending from the first contact end
51a to the second contact end 51b. The electroconductive rubber
connector 50 is sandwiched and pressed between a component such as
a housing W and the connection object P such as a circuit board to
which the stretchable wiring member 11 is electrically connected.
The stretchable wiring member 11 of the present embodiment has a
waterproofing rib 20c that is formed of the flexible substrate 20
so as to surround the electroconductive rubber connector 50 and
protrude from a front surface 20a of the flexible substrate 20. The
other surface of the flexible substrate 20 opposite to the front
surface 20a is a back surface 20b.
[0050] The electroconductive rubber composite that constitutes the
electroconductive rubber connector 50 can be obtained by dispersing
an electroconductive filler in a liquid polymer composite, placing
the composite in a magnetic field and orienting (or aligning)
electroconductive filler particles in an electric connection
direction, and solidifying the liquid polymer composite. Thus, the
electroconductive rubber composite has the electrode 51 that is
surrounded by an insulating cover portion 52 formed of the
solidified polymer composite. In the electrode 51, the
electroconductive filler particles are continuously connected. When
the electrode 51 is observed as a whole, it seems that the
electrode 51 is made only of the electroconductive filler. When the
electrode 51 is observed closely, however, the electroconductive
filler particles are oriented inside the rubber-like elastic body.
Accordingly, even if the amount of the electroconductive filler
mixed therein is small, the electric resistance of the electrode 51
can be reduced while the electrode 51 has an appropriate
flexibility. The electroconductive rubber composite, in which the
electroconductive filler particles are dispersed in a rubber-like
polymer material, also can be obtained in a way different from the
above, in other words, by dispersing electroconductive filler
particles uniformly in a flexible polymer material.
[0051] The rubber-like elastic body fills spaces among the
electroconductive filler particles of the electrode 51 is made of
the same material as that of the cover portion 52. An example of
the electroconductive filler is granular, fibrous, fragmental, or
filamentous metal particles. More specifically, the
electroconductive filler may be particles of nickel, cobalt, iron,
ferrite, or an alloy containing a large amount of these metals, or
particles of a highly conductive metal such as gold, silver,
platinum, aluminum, copper, iron, palladium, chromium, or of an
alloy such as stainless steel, or particles of a resin or ceramic
powder or fiber coated with a magnetic electroconductive material,
or a magnetic electroconductive particles of which the particles
are coated with a highly conductive metal. The metal particles may
have an average diameter of approximately 1 to 200 In this range,
particles can be efficiently oriented, and can enter a linked
state, in directions parallel to lines of magnetic force in the
magnetic field generated in a molding die.
[0052] The cover portion 52 is integrated with the electrode 51 so
as to cover and protect the electrode 51 except for exposed
portions that serve as contact points. The cover portion 52 is
formed of an insulating rubber-like elastic body. For example, the
material of the rubber-like elastic body may be natural rubber or
silicone rubber, isoprene rubber, butadiene rubber,
acrylonitrile-butadiene rubber, 1,2-polybutadiene,
styrene-butadiene rubber, chloroprene rubber, nitrile rubber, butyl
rubber, ethylene-propylene rubber, chlorosulfonated rubber,
polyethylene rubber, acrylic rubber, epichlorohydrin rubber, fluoro
rubber, urethane rubber, styrenic thermoplastic elastomer, olefinic
thermoplastic elastomer, polyester thermoplastic elastomer,
polyurethane thermoplastic elastomer, polyamide thermoplastic
elastomer, polyvinyl chloride thermoplastic elastomer,
thermoplastic fluoroelastomer, or ionically crosslinked
thermoplastic elastomer. Of these materials, a silicone rubber is
preferable because the silicone rubber has good electrical
insulation and favorable environmental characteristics. In
addition, in the case of the electroconductive rubber connector 50
being produced by heating the material in a die, it is preferable
to use a thermosetting rubber. It is more preferable to use a
silicone rubber or a fluoro rubber because of their thermal
resistance.
[0053] The hardness of the cover portion 52 is preferably in the
range of 5 to 70 in A-hardness in accordance with JIS K6253, and
more preferably in the range of 15 to 50. If the hardness exceeds
25 in A-hardness, compression of the electroconductive rubber
connector 50 requires an increased amount of compressive load,
which thereby increases the load applied to the connection object P
and to the housing W. If the hardness is lower than 5.0 in
A-hardness, the electroconductive rubber connector 50 is smashed
and buckled easily when compressed, which tends to separate the
particles easily from each other and may not provide stable
conductivity.
[0054] The waterproofing rib 20c is a portion to be positioned
between the flexible substrate 20 and the connection object P. When
the waterproofing rib 20c is brought into press contact with the
connection object P by pressing the stretchable wiring member 11,
the waterproofing rib 20c isolates the electrode 51 from outside
and prevents water from entering the electrode 51. The
waterproofing rib 20c of the present embodiment protrudes from the
front surface 20a of the flexible substrate 20. The waterproofing
rib 20 is a continuous protrusion shaped like a ring as viewed in
plan. Due to the waterproofing rib 20c being provided around the
electroconductive rubber connector 50, the stretchable wiring
member 11 can reduce the negative impact of water even in a
splashing water environment, which can expand the application area
of the stretchable wiring member 11.
[0055] Second Connector 70: The stretchable wiring member 11 has a
connector portion to be electrically connected to a connection
object P, such as a circuit board. The second connector 70 is a
portion that is directly fixed, using a holding member 71, to a
terminal portion P2 of a flexible cable P1 or the like.
[0056] The stretchable wiring lines 30 of the stretchable wiring
member 11 are electrically connected to wiring P3 of the terminal
portion P2 included in the connection object P. The holding member
71 fixes the stretchable wiring member 11 to the connection object
P to maintain an electrical connection. The terminal portion P2 is
formed of a resin film or the like, and the wiring P3 is formed of
a metallic foil, such as copper foil. The holding member 71, which
is made of a rubber material having flexibility, such as silicone
rubber, is fixed to the flexible substrate 20 of the stretchable
wiring member 11 and also to the terminal portion P2 of the
connection object P.
[0057] Body Sensor 60: Among the connector portions of the
stretchable wiring member 11 for electrical connection with the
connection objects P, such as a circuit board, the body sensor 60
is a portion to be brought into contact, for example, with human
skin surface. The electrode 61 of the body sensor 60 has an outer
shape slightly larger than the electroconductive rubber connector
50 and is designed to have a large contact area to be in contact
with an object such as skin. The body sensor 60 can be provided
when the stretchable wiring member 11 is applied, for example, to
measure body surface potentials. The electrode 61 of the present
embodiment serves as a "hard member" according to the present
invention. The large contact area can reduce stress concentration
on the skin surface to be in contact with and improve contact
stability when the electrode 61 is brought into close contact with
the skin of human body to measure surface potentials. If the
electrode 61 were formed like a metallic pin having a narrow
contact point, stress would be concentrated at the point, giving an
uncomfortable fit feeling. The electrode 61 is required to have a
more or less large area.
[0058] The electrode 61 has a recess 61a formed therein. The recess
61a is formed by chipping off an edge portion of the electrode 61
located near the stretchable wiring line 30. Accordingly, if the
electrode 61 is projected on a picture plane in the thickness
direction of the flexible substrate 20, the recess 61a is present
within the boundary of the projected electrode 61. An extension
layer portion 80 of the flexible substrate 20, which will be
described later, is formed as a filling portion for filling the
recess 61a. A contact portion 31 is formed on the body sensor 60.
The contact portion 31 is made of the same material as that of the
stretchable wiring line 30 and has such a shape that an end portion
of the stretchable wiring line 30 is expanded in the width
direction thereof, which enables electrical contact in a wide area
between the stretchable wiring line 30 and the body sensor 60.
[0059] The electrode 61 of the body sensor 60 is different from the
electrode 51 of the electroconductive rubber connector 50 in the
following points. The electrode 61 of the body sensor 60 is a
contact point member 40 of which the electroconductive filler is
carbon powder. Accordingly, the electrode 61 is superior in
corrosion resistance and weatherability. The electrode 61 is
slightly harder than the electrode 51 of the electroconductive
rubber connector 50 and exhibits a resistance higher than that of
the stretchable wiring line 30. The electrode 61, of which the
conductive portion is made of the carbon material, has a higher
electrical resistance than that of the stretchable wiring line 30.
The electrode 61 is preferably formed so as to have a constant
distance between the stretchable wiring line 30 and the contact
surface of the electrode 61 to be in contact with the skin, and the
stretchable wiring line 30 is preferably laminated on the body
sensor 60 in an area as wide as possible. This enables the
resistance to be constant between the stretchable wiring line 30
and the contact surface of the electrode 61 to be in contact with
the skin, whatever portion of the electrode 61 the skin comes into
contact with. That is why the stretchable wiring line 30 has the
wide contact portion 31.
[0060] Extension Layer Portion 80: The extension layer portion 80
is a portion provided for the purpose that the flexible substrate
20 cannot come off easily from the connection surface with a hard
portion, such as the electrode 61 of the contact point member 40.
As illustrated in the partially enlarged regions R5 and R6 of FIG.
2, the extension layer portion 80 is formed as a thick filling
portion that fills the recess 61a of the electrode 61. The
extension layer portion 80 is formed so as to come into contact
with the inside surface of the recess 61a and also with the surface
of the stretchable wiring line 30 that faces the recess 61a.
Accordingly, if the electrode 61 is projected on a picture plane in
the thickness direction of the flexible substrate 20, the extension
layer portion 80 is positioned within the projected area of the
electrode 61, in other words, positioned inside the outer periphery
(circumference) of the electrode 61 when viewed in plan. Put it
another way, the extension layer portion 80 is formed as a
laminated portion laminated on the upper surface of the electrode
61 (i.e., the inside surface of the recess 61a). The upper surface
of the extension layer portion 80 forms the contact surface with
the stretchable wiring line 30. The stretchable wiring member 11
has a protruding portion (i.e., extension layer portion 80) of
which part of the flexible substrate 20 protrudes along the
stretchable wiring line 30 into the recess 61a of the electrode 61.
In other words, the extension layer portion 80 is formed as the
protruding portion that protrudes into the electrode 61 from a
boundary surface D that is the circumferential surface of the
electrode 61 (i.e., the outer periphery of the above-described
projected area).
[0061] Although the extension layer portion 80 is described as a
portion of the flexible substrate 20, the extension layer portion
80 may be made of a material different from that of the flexible
substrate 20 insofar as the material is more flexible than the
electrode 61. In addition, although the extension layer portion 80
is described as being disposed between the flexible substrate 20
and the electrode 61, the extension layer portion 80 may be
disposed between the stretchable wiring line 30 and a hard member
other than the electrode 61. For example, the electroconductive
rubber connector 50 and the second connector 70 may be formed as
hard members. In this case, a recess may be formed at each hard
member, and the extension layer portion 80 may be formed so as to
fill the recess.
[0062] As the electrode 61 is viewed in plan, the boundary of a
contact area between the stretchable wiring line 30 and the
electrode 61 is positioned inside the outer periphery of the
electrode 61. In other words, the contact portion 31 of the
stretchable wiring line 30 is positioned so as to fit within the
upper surface area of the electrode 61 (in other words, positioned
inside the circumference of the upper surface of the electrode 61).
Accordingly, when the stretchable wiring member 11 is stretched,
the extension layer portion 80 can mitigate the stress generated on
the boundary surface between the flexible substrate 20 and the
electrode 61 and thereby prevent the stretchable wiring line 30
from breaking.
[0063] The body sensor 60 (the electrode 61) has a recess 61a
formed where the extension layer portion 80 is disposed. Put it
another way, the extension layer portion 80 is a portion of the
flexible substrate 20 that enters the recess 61a formed in the body
sensor 60. As described above, the recess 61a is formed in the body
sensor 60, and the flexible substrate 20 is formed so as to enter
the recess 61a. In addition, the surface of the flexible substrate
20 and the surface of the body sensor 60 are made so as to be flush
with each other. This enables the stretchable wiring lines 30 to be
formed, for example, by printing. This makes the manufacturing
easier.
[0064] Next, a manufacturing method of the stretchable wiring
member 11 will be described. The stretchable wiring member 11 can
be manufactured in various ways. One example is described as
follows. As illustrated in FIG. 3, a first segment of the flexible
substrate 20 is produced. To produce the first segment, the
flexible substrate 20 having a half thickness is molded integrally
with the electrodes 61 of the body sensors 60. Subsequently, the
stretchable wiring lines 30 and the contact portions 31 are printed
on the surface of the first segment, for example, by screen
printing. A second segment of the flexible substrate 20 is also
produced. To produce the second segment, the flexible substrate 20
having a half thickness is formed integrally with the
electroconductive rubber connector 50, for example, by insert
molding. Subsequently, the second segment is adhered onto the first
segment. The second connector 70 is formed when the first segment
and the second segment are adhered to each other. The terminal
portion P2 of the flexible cable P1 is inserted between the first
segment and the second segment, and the terminal portion P2 is
fixed using a holding member 71. The stretchable wiring member 11
can be thus manufactured. According to this manufacturing method,
the flexible substrate 20 is molded integrally with the electrodes
61 and the electroconductive rubber connector 50. As a result, the
electrodes 61 and the electroconductive rubber connector 50 can be
integrated firmly into the flexible substrate 20, which can reduce
the likelihood of the electrodes 61 and the electroconductive
rubber connector 50 being detached from the flexible substrate 20
by repeated stretching deformation of the flexible substrate
20.
[0065] The electroconductive rubber connector 50 in which the
electrode 51 and the cover portion 52 are integrally formed can be
manufactured in advance, for example, by injecting a polymer liquid
with an electroconductive filler mixed therein into a molding die,
forming conduction paths by orienting the electroconductive filler
by magnetic poles disposed in the molding die, and then solidifying
the polymer liquid. The electroconductive rubber connector 50 is
subsequently integrated into the second segment of the flexible
substrate 20 as described above. Alternatively, the
electroconductive rubber connector 50 may be formed simultaneously
when the second segment of the flexible substrate 20 is formed.
Still alternatively, an electroconductive rubber having a
predetermined electric resistance may be formed in advance into the
shape of the electrode 51.
[0066] The stretchable wiring member 11 obtained as described above
has the extension layer portion 80 formed at the boundary between
each electrode 61 and the stretchable wiring line 30 extending from
the electrode 61. As a result, the extension layer portion 80
mitigates the stress concentrated at the boundary when the
stretchable wiring member 11 is stretched, which can prevent the
stretchable wiring line 30 from breaking easily in the vicinity of
the boundary.
Modification Example 1-1 [FIGS. 4]
[0067] A stretchable wiring member 12 of the present embodiment is
different from the stretchable wiring member 11 of the first
embodiment in that the extension layer portion 80 and its vicinity
are configured differently. In other words, as illustrated in the
enlarged views of the body sensor 60 of FIG. 4, the extension layer
portion 80 is laminated on the flat upper surface of the electrode
61 of the body sensor 60. The stretchable wiring line 30 is formed
so as to extend obliquely upward and climb the extension layer
portion 80 from the contact portion 31 that is in electrical
contact with the electrode 61. Also with this configuration of the
stretchable wiring member 12, the extension layer portion 80 can
mitigate the stress concentrated at the boundary between the
electrode 61 and the stretchable wiring line 30, which can prevent
the stretchable wiring line 30 from breaking easily in the vicinity
of the boundary.
Second Embodiment [FIGS. 5 to 6]
[0068] FIG. 5 is a plan view of a stretchable wiring member 13 in
which the flexible substrate 20 is assumed to be transparent. FIG.
6 are cross-sectional views of the stretchable wiring member 13.
Compared with the stretchable wiring member 11 of the first
embodiment, the stretchable wiring member 13 of the present
embodiment has a different configuration near the body sensor 60.
In other words, the stretchable wiring line 30 extending from a
second body sensor 60 is disposed so as to overlap a first body
sensor 60. In the present embodiment, an extension layer portion 85
is provided at a position at which the stretchable wiring line 30
extending from the second body sensor 60 overlaps the first body
sensor 60. The extension layer portion 85 enables the stretchable
wiring line 30 connected to the second body sensor 60 to be
disposed over the electrode 61 of the first body sensor 60 in an
electrically isolated manner.
[0069] Regarding the stretchable wiring member 11, the contact
point members 40, such as body sensors 60, were required to be
disposed in a limited area in response to the demand of size
reduction. In addition, it was difficult to adopt a multilayer
arrangement of the stretchable wiring lines 30 due to cost
limitation and avoidance of a warping problem. Under this
situation, it was necessary to lay out the stretchable wiring lines
30 flatly in such a manner that a stretchable wiring line 30
connected to a far side electrode 61 was disposed so as to detour
around a near side electrode 61, as is the case for the stretchable
wiring member 11 described in the first embodiment. The
configuration of the present embodiment, however, can eliminate the
necessity of the stretchable wiring lines 30 detouring around.
[0070] More specifically, as illustrated in FIG. 6B, the electrode
61 of the body sensor 60 has a flat upper surface and a recess 61a
formed in the upper surface. The extension layer portion 85 is
formed so as to fill the recess 61a, and a stretchable wiring line
30 is formed on the extension layer portion 85. Accordingly, the
stretchable wiring line 30 is electrically isolated from the
electrode 61 by the extension layer portion 85. The extension layer
portion 85 formed in the flexible substrate 20 separates the
stretchable wiring line 30 from the electrode 61 in the thickness
direction. The extension layer portion 85 serves as an isolation
portion 88 in which the stretchable wiring line 30 and the
electrode 61 do not have a contact portion. By providing the
isolation portion 88, the stretchable wiring lines 30 can be
disposed without detouring around in the stretchable wiring member
13. The isolation portion 88 also reduces the likelihood of
breakage of the stretchable wiring lines 30. Another difference is
that the stretchable wiring member 11 has an electroconductive
rubber connector 50 disposed only at one end, whereas the
stretchable wiring member 13 has electroconductive rubber
connectors 50 disposed at respective ends thereof. Moreover, the
stretchable wiring member 13 has a conduction-path-shape retaining
member 90 disposed under the electroconductive rubber connector 50,
whereas the stretchable wiring member 11 does not have this
member.
[0071] The conduction-path-shape retaining member 90 is disposed so
as to overlap the electrode 51 as viewed in the thickness direction
of the stretchable wiring member 13. The conduction-path-shape
retaining member 90 can reduce the deformation of the electrode 51
that is vulnerable to deformation in the stretching direction when
the stretchable wiring member 13 is stretched. The
conduction-path-shape retaining member 90 is formed like a plate.
The conduction-path-shape retaining member 90 may be made of a
material having such hardness that the conduction-path-shape
retaining member 90 is not stretched in in-plane directions of the
plate. More specifically, the conduction-path-shape retaining
member 90 may be formed, for example, of a resin film, such as a
polyethylene terephthalate film or a polyimide film, a hard resin
compact, such as a hard resin substrate, or a ceramic substrate or
a metal film. It is sufficient that the conduction-path-shape
retaining member 90 has a hardness to the level of the flexible
substrate 20 or more. Accordingly, a thermosetting rubber and a
thermoplastic elastomer that are harder than the flexible substrate
20 can be used.
[0072] The stretchable wiring member 13 can be manufactured by
producing the first segment and the second segment of the flexible
substrate 20 each having a half thickness and by laminating the
first segment and the second segment on each other, which is
similar to the manufacturing method described in the first
embodiment. The first segment of the stretchable wiring member 13
having the body sensors 60 is formed first. The flexible substrate
20 is molded integrally with the body sensors 60 in such a manner
that the upper surface of each body sensor 60 is flush with the
surface of the extension layer portion 80. Subsequently, the
stretchable wiring lines 30 are formed thereon by printing. The
first segment is laminated on the second segment of the flexible
substrate 20 of the stretchable wiring member 13. The stretchable
wiring member 13 can be thus manufactured.
[0073] In the stretchable wiring member 13, the stretchable wiring
line 30 connected to the second electrode 61 is laminated on the
first electrode 61 in the thickness direction of the stretchable
wiring member 13 with the extension layer portion 80 interposed
therebetween. In other words, the stretchable wiring line 30
connected to the second electrode 61 can be spaced from the first
electrode 61 by the insulating extension layer portion 85.
Accordingly, the stretchable wiring line 30 can be laminated on the
first electrode 61 with no electrical connection therebetween,
which can reduce the width of the stretchable wiring member 13.
Third Embodiment [FIGS. 7 to 9]
[0074] A stretchable wiring member 14 according to a third
embodiment is configured to have both features of the first
embodiment and the second embodiment. In other words, of the four
body sensors 60 illustrated in FIG. 7, each of two peripherally
disposed body sensors 60 illustrated in a partially enlarged region
R12 of FIG. 7 has two types of extension layer portions, in other
words, the extension layer portion 80 and the extension layer
portion 85 (FIG. 9). More specifically, as illustrated in a
partially enlarged region R13 of FIG. 9A, the extension layer
portion 80 included in the stretchable wiring member 14 is similar
to the extension layer portion 80 of the stretchable wiring member
11 of the first embodiment. In addition, as illustrated in FIG. 9B,
the stretchable wiring member 14 also has an isolation portion 88
that includes an extension layer portion 85, which is similar to
the extension layer portion 85 of the stretchable wiring member 13
of the second embodiment.
[0075] As illustrated in FIG. 7, the stretchable wiring member 14
includes four body sensors 60 that have respective extension layer
portions 80. Accordingly, each stretchable wiring line 30 extending
from the corresponding body sensor 60 can be prevented from
breaking at the boundary between the stretchable wiring line 30 and
the body sensor 60. In addition, the two peripherally disposed body
sensors 60 in FIG. 7 have respective extension layer portions 85.
Accordingly, the stretchable wiring line 30 that overlaps each of
the peripherally disposed body sensors 60 can be prevented from
breaking at the boundary at which the stretchable wiring line 30 is
drawn out from the overlapping portion.
Fourth Embodiment [FIG. 10]
[0076] A stretchable wiring member 15 according to a fourth
embodiment has an extension layer portion 80 disposed at the second
connector 70 disposed at an end of the stretchable wiring member
15. In the first embodiment, the second connector 70 of the
stretchable wiring member 11 has the holding member 71 for fixing
the terminal portion P2 of the flexible cable P1 to the flexible
substrate 20, and the holding member 71 is formed of a member
different from the flexible substrate 20. In the stretchable wiring
member 15, however, a portion of the flexible substrate 20 serves
as the holding member 71.
[0077] As illustrated in FIG. 10, the stretchable wiring member 15
has a recess 61a formed by chipping off an edge portion of the
flexible cable P1. The flexible substrate 20 enters the recess 61a
and thereby forms the extension layer portion 80. In the
stretchable wiring member 15, due to the extension layer portion 80
being provided, the stretchable wiring line 30 extending from the
connection portion of the flexible cable P1 can be prevented from
breaking in the vicinity of the connection portion between the
stretchable wiring line 30 and the flexible cable P1.
Modification Example 4-1 [FIG. 11]
[0078] In the stretchable wiring member 16 of the present
embodiment, a connection object P formed of a hard member, such as
the flexible cable P1, is embedded in the flexible substrate 20 at
the second connector 70, as illustrated in FIG. 11. The stretchable
wiring member 16 also has the extension layer portion 80, which is
similar to the stretchable wiring member 15 of the fourth
embodiment. In the stretchable wiring member 16 having the above
configuration, the stretchable wiring line 30 can be prevented from
breaking easily at the boundary between the stretchable wiring line
30 and the flexible cable P1.
Fifth Embodiment [FIGS. 12]
[0079] The stretchable wiring member 17 of the present embodiment
includes an insulating hard member 100 that is different from the
above-described contact point member 40. The extension layer
portion 80 is formed in such a manner that when the hard member 100
is projected on a picture plane in the thickness direction of the
stretchable wiring member 17, a contact surface between the
flexible substrate 20 and the stretchable wiring line 30 is present
inside the projected hard member 100.
[0080] The hard member 100 is made of an insulating hard material
and has such a rigidity as not to be stretched in the stretching
direction of the flexible substrate 20. As illustrated in FIG. 12,
an example of the hard member 100 has a circular shape as viewed in
plan. The shape of the hard member 100, however, is not limited to
the circular shape. For example, the insulating hard material is a
bendable resin film or a hard resin substrate, a thin tabular
member, such as a ceramic substrate, or a lump-like member, such as
a button-like member as illustrated in FIG. 12. The hard member 100
is preferably made of polyimide, phenolic resin, or epoxy resin.
Although a lump-like (button-like) hard member 100 is illustrated
in FIG. 12, the hard member 100 may be shaped like a film (or a
flake) made of a dielectric material and may be configured to serve
as a touch sensor.
[0081] The embodiments described above are examples according to
the present invention. The embodiments may be modified or known
techniques may be added thereto or combined therewith without
departing from the scope of the invention. Such modifications,
additions, and combinations are to be within the scope of the
present invention.
[0082] For example, the extension layer portion 80 is not limited
to that of the stretchable wiring member 11 of the first embodiment
illustrated in FIG. 2. The extension layer portion 80 may assume
various other shapes depending on the shape of the recess 61a of
the electrode 61. For example, as illustrated in FIG. 13A, the
recess 61a of the electrode 61 may be formed as a declining surface
that declines from an end of the contact surface with the
stretchable wiring line 30 so as to be gradually separated from the
stretchable wiring line 30. In this case, the extension layer
portion 80 is shaped so as to fill the gap between the declining
surface and the stretchable wiring line 30. Alternatively, as
illustrated in FIG. 13B, the recess 61a of the electrode 61 may be
formed like a rectangular step. In this case, the extension layer
portion 80 is shaped like a cuboid so as to fill the gap between
the rectangular step and the stretchable wiring line 30. Still
alternatively, as illustrated in FIG. 13C, the recess 61a of the
electrode 61 may be formed like a curved surface. In this case, the
extension layer portion 80 is shaped so as to fill the gap between
the curved surface and the stretchable wiring line 30.
REFERENCE SIGNS LIST
[0083] 11 to 17 stretchable wiring member [0084] 20 flexible
substrate [0085] 20a front surface [0086] 20b back surface [0087]
20c waterproofing rib [0088] 30 stretchable wiring line [0089] 31
contact portion [0090] 40 contact point member [0091] 50
electroconductive rubber connector [0092] 51 electrode [0093] 51a
first contact end [0094] 51b second contact end [0095] 52 cover
portion [0096] 60 body sensor [0097] 61 electrode (hard member)
[0098] 61a recess [0099] 70 second connector [0100] 71 holding
member [0101] 80, 85 extension layer portion [0102] 88 isolation
portion [0103] 100 conduction-path-shape retaining member [0104]
100 hard member [0105] D boundary surface [0106] P connection
object [0107] P1 flexible cable [0108] P2 terminal portion [0109]
P3 wiring [0110] R1 to R13 partially enlarged region
* * * * *